Three different species shrank noticeably about 54 million years ago when the planet suddenly heated up. One of them ‐ an early, compact horse ‐ got 14 percent smaller, going from about 17 pounds (7.7 kilograms) to 14.6 pounds (6.6 kilograms), according to an analysis of fossil teeth in Wednesday's journal Science Advances.I suppose it'll never occur to most people than man did not cause that particular change of the climate, and USA Today ain't a gonna tell 'em, either.
"These guys were probably about the size of maybe a dog, then they dwarfed," said D'Ambrosia. "They may have gone down to the size of a cat."
But wait! There's more!
Previous studies have documented a similar shrinking of mammals, including another early horse ancestor, during an earlier warming about 56 million years ago. Scientists and farmers have also long tracked animals, such as cows, that shrink and give less milk during hotter stretches.